Methods of making articles having toughened and untoughened regions

Abstract

Methods of making an article having at least one toughened region and at least one untoughened region involving providing a material, applying a toughening agent to a portion of the material, shaping the material to produce a preform, applying an untoughened resin to the preform, and curing the preform having the applied untoughened resin to produce the at least one toughened region and the at least one untoughened region wherein the toughened region comprises a toughened resin having a fracture toughness of at least about 1.0 MPa-m^1/2.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This is a Continuation-in-Part of application Ser. No. 11 / 736,319, filed Apr. 17, 2007, which is herein incorporated by reference in its entirety.TECHNICAL FIELD[0002]Embodiments described herein generally relate to methods of making articles having toughened and untoughened regions. More particularly, embodiments herein generally describe methods of making articles from composite materials having toughened and untoughened regions.BACKGROUND OF THE INVENTION[0003]In gas turbine engines, such as aircraft engines, air is drawn into the front of the engine, compressed by a shaft-mounted compressor, and mixed with fuel in a combustor. The mixture is then burned and the hot exhaust gases are passed through a turbine mounted on the same shaft. The flow of combustion gas expands through the turbine, which in turn spins the shaft and provides power to the compressor. The hot exhaust gases are further expanded through nozzles at the back of the en...

AI Technical Summary

Benefits of technology

[0008]Accordingly, there remains a need for methods for manufacturing articles that can provide increased strength to the article in desired regions without increasing the overall weight of the article.

Problems solved by technology

Because engines operate in a variety of conditions, foreign objects may sometimes undesirably enter the engine.

As a result, these foreign objects may impact a fan blade and cause a portion of the impacted blade to be torn loose from the rotor, which is commonly known as fan blade out.

The loose fan blade may then impact the interior of the fan casing at an impact zone, thereby causing a portion of the casing to bulge or deflect.

This deformation of the casing may result in increased stresses along the entire circumference of the fan casing.

These additional layers add undesired weight to the fan casing.

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